Toxic effects of cobalt chloride on hematological factors of common carp (Cyprinus carpio)

Interconnected environmental challenges: heavy metal-drug interactions and their impacts on ecosystems

Industrial expansion and inadequate environmental safety measures are major contributors to environmental contamination, with heavy metals (HMs) and pharmaceutical waste playing crucial roles. Their negative effects are most noticeable in aquatic species and vegetation, where they accumulate in tissues and cause harmful results. Interactions between HMs and pharmaceutical molecules result in the production of metal-drug complexes (MDCs), which have the potential to disturb diverse ecosystems and their interdependence. However, present studies frequently focus on individual pollutants and their effects on specific environmental parameters, leaving out the cumulative effects of pollutants and their processes across several environmental domains. To address this gap, this review emphasizes the environmental sources of HMs, elucidates their emission pathways during anthropogenic activities, investigates the interactions between HMs and pharmaceutical substances, and defines the mechanisms underlying the formation of MDCs across various ecosystems. Furthermore, this review underscores the simultaneous occurrence of HMs and pharmaceutical waste across diverse ecosystems, including the atmosphere, soil, and water resources, and their incorporation into biotic organisms across trophic levels. It is important to note that these complex compounds represent a higher risk than individual contaminants.

Health risk assessment and metal contamination in fish, water and soil sediments in the East Kolkata Wetlands, India, Ramsar site

East Kolkata Wetlands (EKW) is an important site for fish culture in sewage-fed areas, which are major receivers of pollutants and wastages from Kolkata. EKW is internationally important as the Ramsar site was declared on Aug 2002 with an area of 125 km². EKW is a natural water body where wastewater-fed natural aquaculture has been practiced for more than 70 years. It is ecologically vulnerable due to the discharge of toxic waste through sewage canals from cities. Assessing the EKW to understand the inflow and load of the toxic metal (s) in fish, water, and sediments samples is essential. The field (samples collection from 13 sites) and lab (determination of toxic level of metals) based research were carried out to assess metal toxicity and health risk assessment in EKW. The levels of eighteen metals (18), namely Chromium, Vanadium, Cobalt, Manganese, Copper, Nickel, Zinc, Silver, Molybdenum, Arsenic, Selenium, Tin, Gallium, Germanium, Strontium, Cadmium, Mercury, and Lead, were determined using Inductively coupled plasma mass spectrometry (ICP-MS) in five fish tissues viz. muscle, liver, kidney, gill and brain, along with the water samples and soil sediments in 13 sampling sites. The bioaccumulation and concentration of metals in fish tissues, soil sediments, and water samples were well within the safe level concerning the recommendation of different national and international agencies except for a few metals in a few sampling sites like Cd, As, and Pb. The geoaccumulation index (Igeo) was also determined in the soil sediments, indicating moderate arsenic, selenium, and mercury contamination in a few sites. The contamination index in water was also determined in 13 sampling sites. The estimated daily intake (EDI), reference dose (RfD), target hazard quotient (THQ), slope factor and cancer risk of Cr, Mn, Co, Ni, Cu, Zn, As, Se, Cd, Pb and Hg from fish muscle were determined. Based on the results of the present investigation, it is concluded that fish consumption in the East Kolkata Wetland (EKW) is safe. The effects of bioaccumulation of metals in muscle tissue were well within the safe level for consumption as recommended by WHO/FAO.

Significance of extrinsic factors for the optimization of dietary cobalt supplementation in Tor putitora fingerlings

Extrinsic factors play a significant role during aquaculture feed manufacturing practices. Herein, a 90-day feeding trial was designed in triplicate under controlled environmental conditions to evaluate the efficiency of different chemical forms of dietary cobalt at different dosage levels on growth performance, hematological, and immunological indices of Tor putitora fingerlings. Firstly, cobalt chloride nanoparticles (Co-NPs) and cobalt methionine chelated complex (Co-Met) were synthesized via physical and chemical methods respectively and then characterized for their size, surface morphology, and elemental composition analysis by using X-rays diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Results indicated the crystalline nature of Co-NPs with spherical shape having an average size < 20 nm while Co-Met appeared as an amorphous complex with a honey-comb-like octahedral structure with an average size of 82.69 nm. Afterward, a feeding experiment was executed and fish were divided into three groups, i.e., control group (CG; fed 40% crude protein diet with no mineral added), while the other two groups were fed graded levels (0.5-3 mg/kg; increment of 0.5 mg Co/group) of Co-NPs and Co-Met supplemented diets. Statistical analysis of results by using two-way ANOVA indicated significant (P < 0.001) effect of both chemical forms, dosage levels, and their interaction level on fish indicating a dose-dependent significant effect of different chemical forms of dietary cobalt on fish. Additionally, Co-Met supplemented group of fish at supplementation level of 3 mg/kg diet showed highest growth performance, and improved hemato-immunological as compared to other experimental and control group of fish.

Deficiency in Neuroserpin Exacerbates CoCl2 Induced Hypoxic Injury in the Zebrafish Model by Increased Oxidative Stress

Protective strategy against hypoxic-ischemic (H/I) induced injury has been intensively discussed. Neuroserpin, an inhibitor for tissue plasminogen activator (tPA), has been proved a vital neuroprotective agent in cerebral ischemia mouse model and oxygen-glucose deprivation and reoxygenation (OGD/R) cell model. Neuroserpin is a promising therapeutic hint for neonatal hypoxic-ischemia injury. Here, we established a neuroserpin deficient zebrafish to study its role in CoCl₂ chemically induced hypoxic injury. CoCl₂ exposure was beginning at the embryonic stage. Development defects, neuronal loss, and vascular malformation was assessed by imaging microscopy. Neuroserpin deficient zebrafish showed more development defects, neuronal loss and vascular malformation compared to wide-type. Apoptosis and oxidative stress were evaluated to further identify the possible mechanisms. These findings indicate that neuroserpin could protective against CoCl₂ induced hypoxic injury by alleviating oxidative stress.

Toxicity of nickel and cobalt in Japanese flounder

Nickel and cobalt are essential elements that become toxic at high concentrations. Little is known about nickel and cobalt toxicity in aquatic animals. This study aimed to investigate acute and chronic toxicity of nickel and cobalt in Japanese flounder (Paralichthys olivaceous), with emphasis on oxidative stress reactions, histopathological changes, and differences in gene expression. The lethal concentration for 50% mortality (LC₅₀) in 3 and 8 cm Japanese flounder exposed to nickel for 96 h was found to be 86.2 ± 0.018 and 151.3 ± 0.039 mg/L; for cobalt exposure, LC₅₀ was 47.5 ± 0.015 and 180.4 ± 0.034 mg/L, respectively. Chronic nickel and cobalt exposure caused different degrees of oxidative enzyme activity changes in gill, liver, and muscle tissues. Erythrocyte deformations were detected after acute or chronic exposure to nickel and cobalt. the nickel and cobalt exposure also caused pathological changes such as spherical swelling over other gill patches, rod-like proliferations in the gill patch epithelial cell layer, and disorder in hepatocyte arrangement, cell swelling, and cytoplasm loosening. RNA-Seq indicated that there were 184 upregulated and 185 downregulated genes in the liver of Japanese flounder exposed to 15 mg/L nickel for 28 d. For cobalt, 920 upregulated and 457 downregulated genes were detected. Among these differentially expressed genes, 162 were shared by both nickel and cobalt exposure. In both nickel and cobalt, pathways including fatty acid elongation, steroid biosynthesis, unsaturated fatty acid biosynthesis, fatty acid metabolism, PPAR signaling, and ferroptosis were significantly enriched. Taken together, these results aided our understanding of the toxicity of nickel and cobalt in aquatic animals.

Effects of remote ischemic post‑conditioning on fracture healing in rats

Remote ischemic post‑conditioning (RIPC) is an established method to activate the hypoxia‑inducible factor‑1α (HIF‑1α) pathway, which is involved in the impairment of fracture healing. However, the role of RIPC in fracture healing remains to be fully elucidated. In the present study, rats received fractures and were divided into two groups: Control and RIPC, in which hind limb occlusion was performed. Rats were sacrificed at 7, 14, 28 and 42 days subsequent to tibial fracture. Micro‑computed tomography was performed to measure healing of the bone tissue and biomechanical testing was used to test mechanical strength. In addition, the effects of hind limb occlusion on the expression of two primary angiogenic mediators, HIF‑1α and vascular endothelial growth factor (VEGF), as well as the osteoblast markers runt‑related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and osteocalcin (OCN), were determined at the mRNA and protein levels by reverse transcription‑quantitative polymerase chain reaction, western blot analysis and immunohistochemistry. Systemic administration of hind limb occlusion (3 cycles/day, with each occlusion or release phase lasting 10 min) significantly promoted fracture healing and mechanical strength. The present study demonstrated that in rats treated with hind limb occlusion, the expression of HIF‑1α, VEGF, Runx2, ALP and OCN was significantly increased at the mRNA and protein levels, and that RIPC enhances fracture repair in vivo.

Exploring the HIFs, buts and maybes of hypoxia signalling in disease: lessons from zebrafish models

A low level of tissue oxygen (hypoxia) is a physiological feature of a wide range of diseases, from cancer to infection. Cellular hypoxia is sensed by oxygen-sensitive hydroxylase enzymes, which regulate the protein stability of hypoxia-inducible factor α (HIF-α) transcription factors. When stabilised, HIF-α binds with its cofactors to HIF-responsive elements (HREs) in the promoters of target genes to coordinate a wide-ranging transcriptional programme in response to the hypoxic environment. This year marks the 20th anniversary of the discovery of the HIF-1α transcription factor, and in recent years the HIF-mediated hypoxia response is being increasingly recognised as an important process in determining the outcome of diseases such as cancer, inflammatory disease and bacterial infections. Animal models have shed light on the roles of HIF in disease and have uncovered intricate control mechanisms that involve multiple cell types, observations that might have been missed in simpler in vitro systems. These findings highlight the need for new whole-organism models of disease to elucidate these complex regulatory mechanisms. In this Review, we discuss recent advances in our understanding of hypoxia and HIFs in disease that have emerged from studies of zebrafish disease models. Findings from such models identify HIF as an integral player in the disease processes. They also highlight HIF pathway components and their targets as potential therapeutic targets against conditions that range from cancers to infectious disease.

Summary: Hypoxia signalling, mediated by HIF, is a crucial pathway in many disease processes. Here, we review current knowledge of HIF signalling and disease, focusing on recent findings from zebrafish models.

Heavy metals contamination in water and three species of most consumed fish sampled from Caspian Sea, 2011

The present study is an attempt to evaluate the heavy metal contamination in the marine environment of the Caspian Sea of Iran. The concentrations of zinc, chromium, cadmium, and lead were measured in water and dorsal muscle of fish sampled from 10 selected stations along Gorgan coast using atomic absorption spectrophotometry during summer of 2011. The average concentrations of lead in water and fish samples (115.29 ± 14.78 and 113.23 ± 27.01 μg/L) were significantly higher than that of cadmium and chromium (P < 0.05). The highest heavy metals content was observed in Cyprinus carpio samples. The heavy metals concentrations in the samples were within the acceptable recommended standards. But, elevating levels of heavy metals in water and fish made a serious concern about ecosystem and food chain contamination. It is recommended that protective authorities should carry out a continual assessment on the levels of pollutants in the sea.

Evaluation of metal pollution in fish and water collected from Gorgan coast of the Caspian Sea, Iran

In this study, concentrations of zinc, chromium, cadmium and lead were determined in water and three species of fish sampled from 10 selected stations along Gorgan coast using atomic absorption spectrophotometery, summer 2009. Mean lead levels in water and fish samples (119.50 ± 22.24 μg/L and 113.80 ± 33.11 μg/kg) were significantly higher than that of cadmium and chromium (p < 0.05). Cyprinus carpio had highest metals content than Mugila auratus and Rutilus frisikutum. The evaluated metals values in water collected from Gomishan wetland (Pb, Cd, Cr and Zn values are 145.31 ± 35.32, 120.46 ± 11.44, 96.47 ± 6.05 and 82.02 ± 34.37 μg/L, respectively) were higher than the other sampling sites. The result is consistent with the findings accessed by evaluation of the metals in fish specimens. The metals concentrations in the fish and water samples were below the recommended limits. But, elevating levels of metals in water and fish made a serious concern about ecosystem and food chain contamination.

Effects of cobalt nanoparticles on human T cells in vitro

Limited information is available on the potential risk of degradation products of metal-on-metal bearings in joint arthroplasty. The aim of this study was to investigate the cytotoxicity and genotoxicity of orthopedic-related cobalt nanoparticles on human T cells in vitro. T cells were collected using magnetic CD3 microbeads and exposed to different concentrations of cobalt nanoparticles and cobalt chloride. Cytotoxicity was evaluated by methyl thiazolyl tetrazolium and lactate dehydrogenase release assay. Cobalt nanoparticles dissolution in culture medium was determined by inductively coupled plasma-mass spectrometry. To study the probable mechanism of cobalt nanoparticles effects on T cells, superoxide dismutase, catalase, and glutathione peroxidase level was measured. Cobalt nanoparticles and cobalt ions could inhibit cell viability and enhance lactate dehydrogenase release in a concentration- and time-dependent manner (P < 0.05). The levels of cobalt ion released from cobalt nanoparticles in the culture medium were less than 40% and increased with cobalt nanoparticles concentration. Cobalt nanoparticles could induce primary DNA damage in a concentration-dependent manner, and the DNA damage caused by cobalt nanoparticles was heavier than that caused by cobalt ions. Cobalt nanoparticles exposure could significantly decrease superoxide dismutase, catalase, and glutathione peroxidase activities at subtoxic concentrations (6 μM, <CC(50)). These findings suggested that cobalt nanoparticles could generate potential risks to the T cells of patients suffer from metal-on-metal total hip arthroplasty, and the inhibition of antioxidant capacity may play important role in cobalt nanoparticles effects on T cells.

Goldfish exposure to cobalt enhances hemoglobin level and triggers tissue-specific elevation of antioxidant defenses in gills, heart and spleen

Cobalt ions can enhance the generation of reactive oxygen species (ROS), which may be the reason for cobalt toxicity. This study aimed to determine whether Co(2+) toxicity in goldfish is related to induced oxidative stress in gills, heart and spleen, and to assess responses of antioxidant systems. Exposure of goldfish to 50, 100 and 150 mg L(-1) of Co(2+) for 96 h elevated total hemoglobin in blood by 23, 44 and 78%, respectively. In gills, cobalt exposure enhanced lipid peroxide levels and activities of primary antioxidant enzymes; superoxide dismutase (SOD) rose by 125% and glutathione peroxidase (GPx) increased by 53-296%. Glutathione-S-transferase (GST) activity also increased by 117-157% and glucose-6-phosphate dehydrogenase (G6PDH) enhanced by 46-96%. Heart showed limited effects of fish exposure to 50 or 100 mg L(-1) of Co(2+), but the exposure to 150 mg L(-1) of Co(2+) elevated concentrations of lipid peroxides by 123% and activities of GPx by 98% and SOD by 208%. The most substantial effects of goldfish exposure to Co(2+) were observed in spleen: a decrease in total protein concentration by 44-60% and high molecular mass thiols by 59-82%, reduced activities of catalase by 24-58% and GR by 25-68%, whereas the level of low molecular mass thiols increased by 153-279% and activities of GPx, GST, G6PDH were enhanced by 114-120%, 192-769%, and 256-581%, respectively. The data show that fish exposure to 50-150 mg L(-1) of Co(2+) elevates blood hemoglobin level, mimicking effects of hypoxia, and causes the activation of defense systems against ROS.

Heavy metals (Zn, Pb, Cd and Cr) in fish, water and sediments sampled form Southern Caspian Sea, Iran

Environmental pollution is a worldwide problem, heavy metals belonging to the most important pollutants. The progress of industries has led to increased emission of pollutants into ecosystems. Southern Caspian Sea coast is one of the most important aquasystems at the eastern south of Caspian Sea, which receives effluents discharges from heavily industrialized and highly populated settlements. Metals tend to accumulate in water and move up through the food chain. So, studies to ascertain the level of heavy metals in environment and determine potentially hazardous levels for human are necessary. In this investigation, concentration of four heavy metals (zinc [Zn], chromium (Cr), cadmium, [Cd] and lead [Pb]) in three species of most-consumed fishes, water and sediments have been determined. Samples were collected from 10 stations along the Southern coast of Caspian Sea, in spring 2008. Heavy metal concentrations were measured by graphite furnace atomic absorption spectrometry. Then, the data were analyzed by means of one-way analysis of variance (ANOVA) statistical analysis. The results showed that the highest concentration of heavy metals in water and fish and sediment samples were related to Pb and Zn. The minimal and maximal concentrations of these metals in fishes, water and sediments were 53.67-2360.67 and 50.36-2497.25 for Pb and Zn, respectively. However, the observed heavy metals concentrations in fish, water and sediments were below the recommended limits. The investigation showed elevating levels of heavy metals in environment. Thus, a serious notification to industrial and manmade pollution, which can lead to ecosystem and food chain contamination, is necessary.